System and methods for permitting open access to data objects and for securing data within the data objects

ABSTRACT

A system and methods for permitting open access to data objects and for securing data within the data objects is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. According to one embodiment of the present invention, a method for securing a data object is disclosed. The method includes the steps of (1) providing a data object comprising digital data and file format information; (2) embedding independent data into a data object; and (3) scrambling the data object to degrade the data object to a predetermined signal quality level. The steps of embedding and scrambling may be performed until a predetermined condition is met. The method may also include the steps of descrambling the data object to upgrade the data object to a predetermined signal quality level, and decoding the embedded independent data. The additional steps of descrambling and decoding may be performed until a predetermined condition is met. The predetermined condition may include, for example, reaching a desired signal quality of the data object.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/383,879, filed Mar. 30, 2009 now U.S. Pat. No. 7,813,506, which is acontinuation of U.S. application Ser. No. 11/647,861, filed Dec. 29,2006 (issued as U.S. Pat. No. 7,532,725), which is a continuation ofU.S. application Ser. No. 09/731,039, filed Dec. 7, 2000 (issued as U.S.Pat. No. 7,177,429), and U.S. application Ser. No. 09/731,039, filedDec. 7, 2000 (issued as U.S. Pat. No. 7,177,429) claims the benefit ofU.S. Provisional Application No. 60/169,274, filed Dec. 7, 1999, andU.S. application Ser. No. 09/731,039, filed Dec. 7, 2000 (issued as U.S.Pat. No. 7,177,429) claims the benefit of U.S. Provisional ApplicationNo. 60/234,199, filed Sep. 20, 2000. U.S. application Ser. No.12/383,879, filed Mar. 30, 2009 is hereby incorporated by reference, inits entirety. The previously identified patents and/or patentapplications are hereby incorporated by reference, in their entireties.

This application is related to U.S. application Ser. No. 08/674,726,filed Jul. 2, 1996 (issued as U.S. Pat. No. 7,362,775); U.S. applicationSer. No. 08/999,766, filed Jul. 23, 1997, (issued as U.S. Pat. No.7,568,100); U.S. application Ser. No. 09/046,627, filed Mar. 24, 1998,(issued as U.S. Pat. No. 6,598,162); U.S. application Ser. No.09/053,628, filed Apr. 2, 1998, entitled “Multiple Transform Utilizationand Application for Secure Digital Watermarking” (issued as U.S. Pat.No. 6,205,249); U.S. application Ser. No. 09/281,279, filed Mar. 30,1999, entitled “Optimization Methods for the Insertion, Protection, andDetection of Digital Watermarks in Digital Data” (issued as U.S. Pat.No. 6,522,767); U.S. Provisional Application 60/169,274, filed Dec. 7,1999, entitled “Systems, Methods And Devices For Trusted Transactions”;U.S. application Ser. No. 09/456,319, filed Dec. 8, 1999, entitled“Z-Transform Implementation of Digital Watermarks” (issued as U.S. Pat.No. 6,853,726); U.S. application Ser. No. 09/545,589, filed Apr. 7,2000, entitled “Method and System for Digital Watermarking” (issued asU.S. Pat. No. 7,007,166); U.S. application Ser. No. 09/594,719, filedJun. 16, 2000, entitled “Utilizing Data Reduction in Steganographic andCryptographic Systems”, which is a continuation-in-part of InternationalApplication PCT/US00/06522, filed Mar. 14, 2000, and InternationalApplication PCT/US00/06522, filed Mar. 14, 2000 claims the benefit ofU.S. Provisional 60/125,990, filed Mar. 24, 1999, (issued as U.S. Pat.No. 7,123,718); U.S. application Ser. No. 10/049,101, filed Jul. 23,2002, which is a national stage entry of International ApplicationPCT/US00/21189, filed Aug. 4, 2000, and International ApplicationPCT/US00/21189, filed Aug. 4, 2000 claims the benefit of U.S.Provisional 60/147,134, filed Aug. 4, 1999, and InternationalApplication PCT/US00/21189, filed Aug. 4, 2000 claims the benefit ofU.S. Provisional Application 60/213,489, filed Jun. 23, 2000, both U.S.Provisional 60/147,134, filed Aug. 4, 1999 and U.S. ProvisionalApplication 60/213,489, filed Jun. 23, 2000 are entitled “A SecurePersonal Content Server”) (issued as U.S. Pat. No. 7,475,246); U.S.application Ser. No. 09/657,181, filed Sep. 7, 2000, entitled “MethodAnd Device For Monitoring And Analyzing Signals” (issued as U.S. Pat.No. 7,346,472); U.S. Provisional 60/234,199, filed Sep. 20, 2000,entitled “Improved Security Based on Subliminal and SupraliminalChannels For Data Objects”; U.S. application Ser. No. 09/956,262, filedSep. 20, 2001 (issued as U.S. Pat. No. 7,127,615); U.S. application Ser.No. 09/671,739, filed Sep. 29, 2000, entitled “Method And Device ForMonitoring And Analyzing Signals” (now abandoned); and U.S. applicationSer. No. 09/731,039, entitled “Systems, Methods and Devices for TrustedTransactions,” filed Dec. 7, 2000 (issued as U.S. Pat. No. 7,159,116).The previously identified patents and/or patent applications are herebyincorporated by reference, in their entireties.

In addition, this application hereby incorporates by reference, as iffully stated herein, the disclosures of U.S. Pat. No. 5,613,004“Steganographic Method and Device”; U.S. Pat. No. 5,745,569 “Method forStega-Cipher Protection of Computer Code”; U.S. Pat. No. 5,889,868“Optimization Methods for the Insertion, Protection, and Detection ofDigital Watermarks in Digitized Data”; and U.S. Pat. No. 6,078,664,entitled “Z-Transform Implementation of Digital Watermarks.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the monitoring and analysis of digitalinformation. Specifically, the present invention relates to methods andsystems for open access and secured data objects.

2. Description of the Related Art

A number of fundamental issues discourage copyright holders from makingtheir works available for general dissemination while ensuring paymentfor those works. This is especially the case for copyrighted works thatmay be digitally sampled and made available to open networks such as theWorld Wide Web. Various technologies have been proposed that serve toaddress specific problem areas. A synthesis of these technologies mayrepresent a reasonable approach given the nature of networks andcomputation.

SUMMARY OF THE INVENTION

Therefore, a need has arisen for a method for open access and secureddata objects that overcomes the deficiencies of the related art.

According to one embodiment of the present invention, a method forsecuring a data object is disclosed. The method includes the steps of(1) providing a data object comprising digital data and file formatinformation; (2) embedding independent data into a data object; and (3)scrambling the data object to degrade the data object to a predeterminedsignal quality level. The steps of embedding and scrambling may beperformed until a predetermined condition is met. The method may alsoinclude the steps of descrambling the data object to upgrade the dataobject to a predetermined signal quality level, and decoding theembedded independent data. The additional steps of descrambling anddecoding may be performed until a predetermined condition is met. Thepredetermined condition may include, for example, reaching a desiredsignal quality of the data object.

According to another embodiment of the present invention, a method fordistributing a data signal is disclosed. The method includes the stepsof (1) providing a data signal comprising digital data and file formatinformation; (2) selecting a first scrambling technique to apply to thedata signal; (3) scrambling the data signal using the first scramblingtechnique, resulting in a first-level degraded data signal; (4) creatinga first descrambling key for the first-level degraded data signal basedon the first scrambling technique; (5) selecting a second scramblingtechnique to apply to the first-level degraded data signal; (6)scrambling the first-level degraded data signal using a secondscrambling technique, resulting in a second-level degraded data signal;and (7) creating a second descrambling key for the second-level degradeddata signal based on the second scrambling technique.

According to yet another embodiment of the present invention, a methodfor distributing a data object is disclosed. The method includes thesteps of (1) providing a data object comprising digital data and fileformat information; (2) encoding independent authentication data intothe data object; and (3) manipulating the file format information basedon at least one signal characteristic of the data object.

According to still another embodiment of the present invention, a methodfor distributing data signals is disclosed. The method includes thesteps of (1) embedding independent data into a data object; (2)scrambling the data object; (3) distributing the scrambled data object;(4) distributing a predetermined key that enables access to the dataobject; and (5) descrambling the scrambled data object with thepredetermined key.

According to another embodiment of the present invention, a method fordata signal distribution is disclosed. The method includes the steps of(1) applying a steganographic technique for embedding independent datainto the data signal; (2) applying a scrambling technique selected fromthe group consisting of file format manipulation and partial encryption;and (3) generating a predetermined key.

According to another embodiment of the present invention, a method forbandwidth allocation is disclosed. The method includes the steps ofpresenting a plurality of data objects to a user, each data objecthaving a security application, and linking at least a first data objectto a second data object. The first data object may include, for example,advertising. A characteristic of the first data object may cause achange in the second data object.

According to another embodiment of the present invention, a system forsecuring data within a data object is disclosed. The system includes anembedder that embeds independent data into a data object; and ascrambler that scrambles the data object to degrade the data object to apredetermined signal quality level. The system may also include adescrambler that descrambles the data object to upgrade the data objectto a predetermined signal quality level; and a decoder that decodes theembedded independent data.

According to another embodiment of the present invention, a system fordistributing a data signal is disclosed. According to one embodiment ofthe present invention, the system includes a first selector that selectsa first scrambling technique to apply to the data signal; a firstscrambler that scrambles the data signal using the first scramblingtechnique, resulting in a first-level degraded data signal; a first keycreator that creates a first descrambling key for the first-leveldegraded data signal based on the first scrambling technique; a secondselector that selects a second scrambling technique to apply to thefirst-level degraded data signal; a second scrambler that scrambles thefirst-level degraded data signal using a second scrambling technique,resulting in a second-level degraded data signal; and a second keycreator that creates a second descrambling key for the second-leveldegraded data signal based on the second scrambling technique.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a data object that has file format informationwhere a decrease in file size corresponds to a decrease in signalquality according to an embodiment of the present invention.

FIG. 2 is a diagram of a data object with file format information at afull quality signal level according to an embodiment of the presentinvention.

FIG. 3 is a diagram of a data object that has been embedded withindependent data according to an embodiment of the present invention.

FIG. 4 is a diagram of a data object at a quality signal level that isless than that depicted in FIG. 2. The data object in FIG. 4 has a filesize corresponding to fewer accessible embedded independent dataaccording to an embodiment of the present invention.

FIG. 5 is a block flow diagram for embedding and scrambling a dataobject according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the drawings wherein like parts aredesignated by reference throughout, there is illustrated in FIG. 1 adiagram of a data object that has file format information where adecrease in file size corresponds to a decrease in signal quality. Forexample, a DVD Audio signal has a larger file size than an MP3 recordingand corresponding higher quality than the smaller sized file. This isapplicable for any media file, including images, audio, video, and worksthat are multimedia in nature. The largest set of data in FIG. 1corresponds to “A”, the next largest to “B”, and the smallest, forpurposes of illustration, “C”. Each of these sets representpredetermined signal quality levels. Each signal manipulation step maybe governed by a predetermined key, partial key, session key,authorization key, public key pair, or the like, depending on theintended application. Keys may be used singularly or collectively.

In certain embodiments, as described herein, a user receives the entiredata object but is only able to observe the object as limited by thequality and file size that might correspond to “C”. For instance, an MP3level of quality, though the ability to increase the signal quality to“A”, perhaps corresponding to DVD-Audio quality, can be handled in realor near real-time. As discussed in the sample embodiments, streaming ofmedia over networks, such as the Internet, or downloads of content canbe supported.

FIG. 2 corresponds to the manner in which the data object isdistributed, without reference to the predetermined signal qualitylevels in FIG. 2. It may also refer to a separate and distinct dataobject that is linked to another data object. The logical associationsbetween at least two objects may assist with determining the quality ofeither of the objects or both. The objects may represent trade-offsbetween signal quality or quantity, as well as payment, or even methodsfor advertising as discussed in the sample embodiments.

FIG. 3 represents a data object at full quality that has been embeddedwith independent data. Because quality is a threshold for dataembedding, different steganographic techniques may yield differentquantity or quality of embedded independent data. As well, the type ofmedia may have differences and such parameters as channel capacity forthe media, the timing of processing or overhead, as well as overhead forhandling the scrambling and de-scrambling can be flexibly supported. Asthe data object is scrambled, the embedded data is obscured. This doesnot mean embedded data will be erased, but fewer embedded data will beeasily recoverable. This corresponds to FIG. 4. which is not shown toscale. It has been shown that robust open watermarks may be goodcandidates for resisting a wide range of signal manipulations, intendedor unintended, and may serve as an appropriate baseline for of how muchembedded data may be successfully embedded or detected. The inverserelationship between signal quality and the decrease in the number ofdetectable embedded data elements can be used to adjust quality levelsof the data object or objects.

FIG. 5 is a block flow diagram of a method of preparing data objects fordistribution according to an embodiment of the present invention. First,a data object is obtained. Next, independent data is embedded into thedata object. Third, the now embedded data object is degraded to apredetermined signal quality level. The process may be repeated tocreate more tiers of predetermined quality thresholds. The data objectis then ready for distribution.

Cryptography is typically used to establish confidence, data integrityand nonrepudiation of data. The basis for cryptography lies in thedifficulty of solving certain mathematical relationships that may existbetween the uncoded message (i.e., “plaintext”) and the coded message(i.e., the “ciphertext”). A difference between general coding schemes(which are used, for example, for storage and/or transmission of data)and cryptographic schemes is that cryptographic schemes involve theexchange of a “secret.” Symmetric cryptographic protocols permit (forexample, “plaintext”) to be randomly encoded (“ciphertext”) in such amanner so as to allow successful deciphering only with a secret, or“key.” With symmetric ciphering, security is held in the key, whichperforms both encryption and decryption. What remains is thedistribution, or sharing, and protection of the key. The key may beassociated with unique, or independent, data, such as passwords orbiometric information, to further cover the secret in a manner that maybe individualized to users or devices capable of interpreting the uniquedata. The addition of unique data to the key serves to increase thecomputational complexity of discovering the secret.

Techniques have been developed to address the distribution of the keyover public or unsecure communications channels. RSA uses suchasymmetric cryptography in that a private or secret key is used forencryption, and a public key, (whose relationship with the private keycan only be determined with great computational activity), is used toenable decryption. While public key cryptography also introduces theability to carry out digital signature calculations to affix a signatureto the decrypted output to assure nonrepudiation, the computationalrequirements of public key cryptography, including application ofdigital signatures, is thought to be relatively expensive for certainapplications.

Depending on the security issue being addressed, cryptography may beused to secure communications channels or to establish the identity ofusers of a given communications channel Signatures represent a furtherembodiment of tamperproofing data and there are a number of knownspecialized signature functions to achieve various goals (zeroknowledge, one time, subliminal free, etc.). The issue of how toassimilate the ease and inexpensive nature of digital communicationswith secure forms of authentication is thus a problem for which manypotential solutions exist. The digital copy problem, however, may bemore appropriately addressed by combining cryptographic features withsteganography. Steganography is the art of hiding something in plainview.

Efforts to introduce the data integrity features of cryptography withthe data hiding features of steganography resulted in the advent ofdigital watermarking. Digital watermarking, based on steganographicciphering, uses the cryptographic benefits of key creation withperceptual coding schemes to tamperproof digitally sampled data. Suchdata may include images, audio, video, multimedia, etc. Whilecryptographic protocol ensures that the transfer of data may besuccessfully authenticated, only secure digital watermarking mayuniquely identify the data object in a manner consistent with thecharacteristics of the data. Thus, watermark encoders will likely differfor different media objects.

The similarities between watermarking and signature schemes representhow changes or modifications of the data to be secured are mapped to anoutput. With perceptible data, perceptual compression limits theeffectiveness of signatures as the compressed signal will perceptiblyand accurately represent the original signal while reducing irrelevantor redundant data. Signature schemes are not traditionally directed athandling this limitation. Steganographic ciphering or signaturegeneration based on steganography, however, is so directed. Robustdigital watermarking, thus, has additional security limitationsregarding the survival of the watermark and its relationship with theauthentic signal. Combining a robust open watermark (“ROW”) with afragile or forensic watermark for the same digitized signal enables bothrobustness and security parameters to be met.

Some known methods for ensuring data integrity rely on how much accessis provided to users. A problem exists, however, in that many dataobjects are available in formats that lack any protocol for accessrestriction or uniqueness (to assist in auditing copies). The benefitsof widespread digital signal processing has reduced the assumption thatthe data objects need to come from authentic, or authorized, sources.Essentially, the reliance on bandwidth limitations to assure thesecurity of large copyrighted files, such as music and video, has becomemoot as physically stored media is introduced to public networks such asthe Internet. This is known as the digital copy problem, or “piracy.”

A related problem is that many of the schemes once thought to handlethis significant problem, under the rubric of digital rights management(“DRM”), are entirely dependent on the security of the accessrestriction protocol, while ignoring the ease at which “difference”attacks may be applied. A difference attack may be performed bycomparing a common data object in secure (e.g., a watermarked CD) andunsecure (e.g., an unsecure, or legacy CD) formats to yield the secretkey. Moreover, DRM solutions typically stop providing any level ofaccess restriction when the data object is viewed or played by the user.Any claim to the contrary ignores the mathematical equivalence ofciphering with coding. Ironically, DRM solutions are increasinglydesigned with reduced computational requirements in order to meeteconomic realities. This means that cryptographic protocols are designedto handle secure communications, while digitally sampled copyrightedmedia is designed to be widely accessible. The ineffectiveness ofbandwidth limitations to act as a “speed bump” for rampant unauthorizedduplication and redistribution of copyrighted data is best demonstratedby the wild popularity of such file-sharing systems as Napster™,Gnutella, etc. The present invention provides an approach to combinevarious security techniques to address the need for open access of dataobjects while preserving data integrity and payment for the objects.

In cryptography, a number of techniques have been developed to addressthe difficulty of trusting a single entity with certain sensitive data.One technique, based on threshold cryptography, requires more than oneentity to enable the decryption of data by breaking the decryption keyinto partial keys. For instance, sensitive financial information havingan intendent risk for abuse with a single private key may be amelioratedby requiring more than one person to each provide a partial key inconcert to decrypt the sensitive information. In steganography, the lackof present asymmetric embedding protocols, with the exception ofnonlinear encoding techniques, is a direct result of the linearity ofmost perceptual coding schemes. Examples of such nonlinear encodingtechniques are described in U.S. Pat. No. 6,078,664, entitled“Z-Transform Implementation Of Digital Watermarks,” the disclosure ofwhich is incorporated by reference in its entirety.

Cryptographic protocols may be used to increase data integrity insteganographic ciphers, as well as nonlinear coding schemes, such asthose that may be described by z-transforms, and separation of watermarkdetection from decoding (as disclosed in U.S. Pat. No. 6,078,664 andpending U.S. patent application Ser. No. 09/456,319). Nevertheless,computational overhead may ultimately limit how much security can bedirected on watermarking keys. As with threshold cryptography, transferfunction-based key generation offers part of the solution for thepresent invention. This may be analogized to breaking secrets into partsthat, when combined, yield the secret. The secret, or key, for atransfer function-based manipulation of a signal may be broken intoparts to enable dynamic pricing models or models of payments moreclosely representative of a network of users. In this way, it may bebeneficial to price data signals based on time or number of usersseeking the same data objects but perhaps at varying quality levels orby extension payment profiles (subscription, download, a la carte).

Transfer functions represent a class of functions that relate input datato output data. As used in this disclosure, the term “transfer function”is used in the format sense, that is, to refer to that class of transferfunctions that is used to format input data for meaningfulcommunication. A particular format may be chosen to emphasize subjectiveor perceptible measures, or both. When stored in a particular format,the data may be said to have an inherent granularity based on thecharacteristics of the format. The transfer function can be used tomanipulate, or scramble, the input data, for example, based on at leastone signal characteristic of the data object. That is, the input data isscrambled in a way that manipulates the input data at a level of itsinherent granularity in accordance with its transfer function. See U.S.patent application Ser. No. 09/046,627, filed Mar. 24, 1998, entitled“Method for Combining Transfer Function with Predetermined KeyCreation,” (issued as U.S. Pat. No. 6,598,162), which disclosure isincorporated herein by reference.

Compression schemes may be optimized for any number of parameters, suchas robustness, fidelity, speed, etc., and thus, due consideration mustbe given to the granularity of the data for the given format. Thepresent invention seeks to manipulate data in a way that variesdepending on the quality of the data being sought. Thresholds for thisquality measurement enable robust models for security and payment asdescribed herein.

Transfer functions can be used to manipulate data at the inherentgranularity of the file format of the data. While formatting isintrinsically important, for many data operations, the formatting is asmall subset of the overall data being represented. This is of concernbecause of the nature of how data is recognized in real worldapplications. For instance, radio broadcasts are freely accessible, butare delivered at a quality that is inferior to the original recording.For example, a song that is recorded on a Compact Disc may includefrequencies ranging from 20 Hz to 22,000 Hz, but when played on a radioreceiver, the reproduced song typically includes frequencies only in therange of about 300 Hz to about 16,000 Hz. Compact discs have acommercially-based market price, while radio broadcasts are “paid” forby advertising.

The difference in quality is not the sole determinant in how the audiosignal may be valued. However, the ability to broadcast, or stream data,and enable discrete file sharing through the same communicationschannel, such as the World Wide Web, places the model of streaming anddownloads in direct competition. Similarly, designing security to meeteither model is a benefit of the present invention over the prior art.The reasoning behind such comparison, and, by extension, the benefitsoffered by the present invention, relate to how data is perceived by apotential audience of consumers. Additionally, the present inventioncontemplates the steps that need to be applied to assure that the linkbetween perception and payment.

The inherent granularity of the file format of the data may be thoughtof as signal characteristics or signal features. The changes may beassociated with a pseudo-random key, or a cryptographically-generatedkey or key pair, and may be distributed and handled by downstreamparties using existing browser, viewer or player technologies. This isdisclosed in U.S. patent application Ser. No. 09/046,627, entitled“Method For Combining Transfer Functions With Predetermined KeyCreation,” (issued as U.S. Pat. No. 6,598,162), the disclosure of whichis incorporated by reference in its entirety. A benefit of controllingthe quality of a signal as it will be offered to a marketplace ofparticipants may be an important consideration in determining pricing ofthe media. It is also a means for determining the quality threshold atwhich potential consumers may evaluate the data to make a purchasingdecision. An important difference is that cryptography is not directedto the quality of the data, but only to access to the data.

The comparative computational benefit of subjecting a signal to transferfunction-based security, where the key is permanently associated withthe degraded signal, versus faster encryption, is related, indirectly,to the boosts in speed for probabilistic cryptography versus traditionalcryptography. With transfer functions, the key is predetermined tohaving application to some aspect of how the signal is represented. Withencryption, however, no such information exists in order to providesecurity to the ciphertext. Some speed improvements, such as thosedisclosed in U.S. Pat. No. 6,081,597, the disclosure of which isincorporated by reference in its entirety, regard the introduction ofprobabilistic approaches to cryptography in order to speed processingtimes for both encryption and decryption. This approach, however, maynot be attractive because it introduces additional potential weaknessesfor various mathematical properties.

What is clear is that information, as it is currently protected orsecured, needs to have many approaches because, from a businessperspective, it is unclear why some information achieves higherfinancial returns than other information. Assuring open access withsecurity concentrated on the object, (as with watermarking), orconcentrated on the fidelity, (as with transfer functions), may be moreappropriate in view of the lost opportunities caused by accessrestriction with straight cryptography. Enabling the interaction ofusers and sellers to buy or trade value, held in keys, to increase thequality of data objects, is a more market-based approach to a problemfor which few answers currently exist. As well, it provides for a morerobust approach to understanding just what is demanded on a network,even in bandwidth terms, and enables a market-based approach toaccurately charge for bandwidth and content or data objects exchanged onthat bandwidth. The bandwidth is measured in bits per second, wherehigher valued bits increase the optimal pricing of that bandwidth, forany given instant of time.

A further difference is that any cryptography applied to a signal streammay not be related to the characteristics of the signal stream, or thechannel for the signal stream, and thus may be more expensive to boththe sender and receiver of the data. As well, the transfer function keyis a function of the signal or how the signal will be distributed over achannel, so it may be easier to change the transfer function key than toreplace the decryption software of receivers of the data. Intentionaland intrinsic links between the granularity, or quality, of a signal andschemes for authentication or payment may also be used to enablethreshold-based quality settings. Moreover, the transfer function may behandled by existing viewers or players because the format of the data isnot changed, but only the quality of the material in the format ismanipulated.

Examples of threshold-based security include subjecting a data signal toa transfer function-based manipulation associated with acryptographically-generated key or key pair, and embedding unique, orindependent, data in the signal stream that may be logically linked withthe transfer function-based key. This combines transfer functions withsteganographic embedding to force attacks on the signal being sought.The unique information may be short hashes that are both fast and assistin enabling payment of the signal stream upon purchase of thedescrambling key. Each short hash could, for example, represent somepredetermined value given some expectation that some of the hashes maybe lost, but not to affect an overall pricing of the data object.

An example of this combination is as follows. A purchaser observing ascrambled signal stream (with predetermined quality manipulations basedon the transfer functions applied) purchases a key. The key may beparameterized in a manner that is signal-specific. For example, plannedbroadcasts with prerecorded signals may be preanalyzed to enable aperceptible mask for hiding data. In addition, technology to bufferpreanalysis for signals to enhance the processing speed of a subsequentlikely request of a previously preanalyzed signal may be used. Thesignal may also be preanalyzed for levels of degradation based onspecific transfer functions applied to the signal. Channel or timespecific parameters, similar to session keys as practiced incryptography, may be similarly utilized where channels have differentdata objects with different signal-based characteristics that may begrouped more efficiently, such as video and audio. Time-specificparameters may simply foster differences between those objects that arerelatively high in demand at a given time. Additionally, popularpay-per-view systems may be enabled with time dependent parameters.Similar to session keys disclosed for ensuring secure channels (SSL),sessions key applied to information may increase security or enablediscrete payments to be made for various distributed data objects.

One way to measure the threshold of payment is to measure a unit ofpayment against the ability to steganographically embed enoughinformation to perform a successful authentication of paymentinformation. Signature schemes are generally computationally expensiveby orders of magnitude versus message authentication codes or one-wayhashes. Given a relationship between the perceptibility of a signal andthe available space for successfully hiding authentication data, atampered signal stream may suffer both further quality degradation and afailure of the authentication protocols supporting payment mechanisms.Any inverse relationship between the signal quality and the decrease inthe detectable number of payment-based hashes may be used to adjustsignal quality parameters with payment parameters. Reasonableestimations for the cost and expense of embedding hashes, which may bequickly authenticated and reliably associated with payment, have beendemonstrated in a variety of known micropayment schemes.

Digital signatures may also be incorporated at a higher computationalcost to the overall system implementation (e.g., MicroMint, PayWord).See Security Protocols, International Workshop Cambridge, United KingdomApr. 10-12, 1996, Lecture Notes in Computer Science, Vol. 1189 (MarkLomas ed.). These schemes, however, do not integrate signal qualitygenerally with payments. Embedding is largely ignored.

The embedding and scrambling may have some logical relationship that mayform the basis of an allocation of bandwidth or even a means ofestablishing a price for the object, or a demand for the object. Bothtechniques provide a robust framework for authenticating and verifyingthe object's quality, as well as how the network may dynamically adjustthe pricing of the overall bandwidth/objects being demanded by users.

When a given signal contains relatively little noise, there is lessspace for information hiding, and a payment metric maybe adjusted forcommercially valued signals prior to broadcast to estimate a fairpayment model based on measures of successful steganographic embeddingof the payment information in discrete units of time. When a givensignal contains relatively high noise, adjustments over the paymentmetric may be made. Alternatively, or in combination with embeddedpayment information, the distortion introduced by a transfer functionmay be logically associated with the payment and stored in a generalsession key, or in a series of keys propagated from the sender to thereceiver in a discrete series. The receiver may be required to establishcredentials for payment in addition to an identity for material that isdeemed to require prior authorization by the sender. Alternatively, thematerial may be intended for an audience at a particular quality settingthat is commercially free (e.g., “AM radio quality”). As anotheralternative, any of the audience members may purchase keys that have alogical relationship with predetermined commercial pricing (e.g., “CDquality” or live concert event). The present invention anticipatesflexible pricing, open access of signal streams and measuredrelationships with the quality of the signal in the stream. Anychannel-based or time-based restrictions on a given implementation maybe flexibly manipulated to achieve either better pricing orreceiver-sensitive demands to given data objects.

Essentially, the streamed data is openly accessible to any potentialconsumer at a degraded quality (e.g., there is “open access” to thestreamed data in a scrambled or slightly scrambled state). Further,payment data or other such independent data is securely embedded withinthe stream (i.e., there may be secured data hidden within the datastream). Both embedding and scrambled state-dependent settings arecontemplated by the present invention. Purchase of the descrambling keyintroduces a change to the authentication or payment data stream andenables immediate streamed payment to be initiated. Where streamedpayment is not preferred, single payments or installment payments incredit or debt are also possible with embodiments of the presentinvention. Establishing a unique identifier for the user or paymentmeans, such as linking to a phone bill, credit card or alternativepayment facility, may provide additional credentials for the seller touse.

The benefits of such a system (e.g., improved estimation of demand for aparticular data object, reduced cost of security because of theopen-access nature of the data objects, the ability to link quality topayment) are obvious given the difficulty in assessing the commercialvalue of any given data object, especially where the data object may bemade available in a variety of quality settings, live or prerecorded, ordemand-based access limitation (essentially, a direct correlation withrequests for a given data object or object stream and the cost of“handling” all requests). For example, discrete data objects may have avariety of quality levels, ranging from an encrypted version (lowquality) to commercial grade quality. The quality levels may bepredetermined, and may also include embedded data, which may have avariable detection rate based on the predetermined quality threshold. Inaddition, the present invention provides a tighter, more granularestimation of data object demand, as well as a clearer estimation of howa network can be optimized to realize commercial returns. All of thismakes it so that different quality levels, different objects,differential object treatment for objects, which may be advertisinginstead of the content sought (for those situations where the channelmay have a fixed dimension and part of the that fixed dimension includesdata objects not being sought but being provided to pay for the objector objects being sought—this is called secondary or advertising-baseddata), yield-based pricing and demand given that the objects may beavailable in less-than-commercial grade quality instead of no accesswhatsoever for systems in the art.

The present invention also permits greater flexibility. For instance,the transfer function may be engineered to reduce perceptible artifactsas more people choose to pay. In other words, as more consumers pay, theoverall level of quality of the stream increases. In another example,the scrambled states may be preset to make adjustments as users makepayments for descrambling keys. Alternatively, threshold-likeapplication of the transfer function may enable true market-basedpricing of a particular signal or signal stream as access is unfetteredto the initially, but intentionally, degraded signal. Moreover, the linkwith bandwidth costs, which may serve as a floor for the overall pricingof the objects being offered, may constitute part of the embeddedauthentication data prior to purchase (by the user's decision to acquirea descrambling key).

In the case where the data is unknown, such as with new copyrightedmaterial, it may be impossible to combine the signal degradationfeatures of transfer functions if all of the data in a signal stream aresubjected to cryptographic ciphering as is currently a predominantfeature in the prior art. The material is all treated equally and thusthe lowest common denominator is security with encryption and accessrestriction. Differential access is not possible based on signal qualitymeasures and encrypting individual objects is a greater overall costpaid in the computational complexity of full encryption versus transferfunction-based manipulations. The present invention uses transferfunctions as a low-cost means for enabling open access to varying dataobjects, albeit in a downgraded level of quality intrinsic to thecharacteristics of the data, so as to allow for purchase decisions thatmaybe made “on-the-fly.” Another baseline may be made for the embeddingfeatures contemplated herein. The advent of robust open watermarksrepresents a fairly good representation of how a watermark may survivegiven a wide breadth of signal manipulations and subjectiveimperceptibility measures. A ROW may be engineered to survive up to thelimit of the signal quality expected, including perceptual coding (e.g.,MP3, AAC, etc.), and may serve as a baseline for the least amount ofquality for a given signal intended for streaming. Essentially, thesignal quality may be represented as that quality for which a ROW, whichsurvives a predetermined number of signal manipulations, may besuccessfully embedded and detected.

The purchase is the equivalent of the receipt of the cryptographicallygenerated transfer function-based key, or public key, by the user. Thekey may be dependent on the channel, as a session key for rendering thechannel at a pre-transfer function state, where all objects in thechannel are deemed equivalent, as with a concert broadcast, orpredetermined quality, where some objects are less degraded, or notdegraded, to encourage user interest in the channel.

The present invention may also be used to scramble particular dataobjects within a stream that offers higher quality in the stream (e.g.,high definition television versus satellite television) than isotherwise available in other predetermined formats (e.g., standard NTSCquality material of the same television broadcast, or even differencesbetween live versus prerecorded material). Scrambled and unscrambledobjects may be streamed in the same channel without the need forexpensive cryptographic operations. Embedding authentication informationin the stream, or including authentication information in thedescrambling key, is economically inexpensive while being intrinsicallydependent on the signal being sought.

The decision to use such data scrambling instead of full-blownencryption represents a decision to handle data objects as they are, notas the channel handles data absolutely. Thus, the choice of transferfunction-based scrambling may be less prone to generic attacks on anencryption system that addresses data, but does not address datacharacteristics. Encryption systems may suffer implementation weaknessesif a general encryption method encrypts each data object independent ofa comparably inexpensive coding system. Thus, for each encrypted object,there is an underlying coded element that has either been “wrapped” byan encryption function, a file extension, or that each coded element isencrypted, independent on the underlying coding scheme. Hacks will befocused on the objects as they are decrypted without any penalty paid onthe data object or its quality (represented in signal features orcharacteristics based on characteristics, such as, frequency, time,spatial, or bit depth). Total Recorder, Audio Jacker and similarapplications simply route decrypted signal outputs to unsecure locationsin a receiver's general computing device, without the encryption.Comparisons with the previously encrypted stream are now computationaleasy to enable generalized hacks of the system keys.

Distributing security both perceptibly and imperceptibly is largelymissing from the art. If encryption is expensive, it must offer a levelof security consistent with that value. Authentication protocols neednot be expensive in comparison to the coding scheme used by thereceiver. Additionally, the present invention allows for considerationsto be made for transfer functions that are bound by a communicationschannel (a higher number of channels may be utilized with smallerbandwidth requirements, but may also reduce the audience experience foreach channel by lowering overall quality). To address this issue, a dataobject may be preanalyzed to map any manipulations, given demand in thechannel, to the coding scheme for which the channel is designed. Ifpartial encryption is deemed a better security fit, instead of transferfunctions, an encryption scheme that typically has no relationship withthe scrambling of data given signal features or characteristics may beapplied. Fast encryption schemes, such as elliptic curve or thosedisclosed in U.S. Pat. No. 6,081,597, are good candidates.

Data objects may be communicated efficiently given an estimation ofbandwidth resources. The trade-off among the size of the data objects,bandwidth capacity in available channels, and accessibility by receiversof the data objects create parameters for cost and performance.Depending on what data is broadcast in a stream, a variety of securityprotocols may be desired. Copyrighted material seeks the highesteconomic value by first reducing the cost of distribution, and thenensuring as much payment as possible. The cost of distribution is afunction of both recognition and accessibility. Material that isdemanded may not be communicated efficiently over networks for whichsenders and receivers have limited bandwidth (defined as bits persecond, or data per discrete unit of time) prior to those users droppingfrom the system and potentially choosing not to make any purchase.Alternative means for accessing the material, including purchasing thematerial in a physical format that handles the bandwidth limitationsmore effectively (e.g., a prerecorded DVD), act as a physicalrepresentation of the bandwidth resources necessary to satisfyconsumers. The devices that are designed to store the encoded objectsmay be configured to handle the embodiments of the present invention.Alternatively, markets exist for distribution of material in downgradedformats as a result of bandwidth limitations. Examples, such as RealNetworks or Microsoft Media Player applications, offer material informats that have lower absolute quality than that offered by suchphysical media packaging as CD and DVD. There also exist proprietarynetworks with higher channel capacity, such as cable television orsatellite.

The problems of securing a stream of data are similar to securing astored or fixed representation of the same. U.S. Pat. No. 6,009,176, thedisclosure of which is incorporated by reference in its entirety, offersa means for propagating a signature calculation across a stream of data.The computational cost of generating the signature is reduced as theauthentication features of the signature, or additionally generated oneway hashes, in the stream are propagated as ancillary data. Essentially,a hash from a successive block of streamed data is embedded in thecurrent block. The evident weakness of this technology is thecomputational overhead of signature propagation. While it is lessintensive than discretely signing individual blocks, the weakness ofauthenticating a stream of data intended for broadcast is related to theinability to prevent the ancillary authentication information from beingstripped. A more appropriate application of authentication trees, wherean initial hash may apply to any of the children data, at lowercomputational cost, is the scrambling of data objects by transferfunction. Application of such authentication in the stream of dataitself is the basis of steganographic ciphering disclosed elsewhere inthe art, including inventions by the present inventor.

A similar general observation is that authentication may be handled in arudimentary way by observing any damage to an outputted stream.Similarly, crude authentication is possible when observing noisy,unpaid, cable television broadcasts. Dissimilarly from the presentinvention, it is believed that the application of data object specificscrambling, applicable to a streaming channel, affords rightsholders anextra measure of security in the absolute. For example, the thresholdfor dissuading consumers from observing media in downgraded formats hasbeen historically inadequate. Second, it is assumed, arguendo, thatobservation is more likely to lead to purchase for a number ofapplicable markets. However, making data objects uniquely secure is lesscomputationally expensive than a blanket application of anyauthentication or security scheme meant to address the most determinedattacks for several reasons. For instance, not all objects are valuedequally, and thus variable security protocols reduce the burden onaggregators or sellers of said objects. Next, quality has always beenused to encourage recognition and purchasing of data objects such asmedia-rich content. Further, channels may be spilt between data objectsintended for the channel matched with advertisements that are typicallysecondary in value to the user. The ability to mix the quality of bothprimary and secondary data objects being delivered to users in real timeenables additional flexibility in pricing and service offerings tomarkets for data. Lastly, the present invention seeks to tie layeredsecurity, while enabling open access, so as to reduce the potential forsystem-wide failure. By addressing each data object in context with themeans for availability to potential consumers the purchasing experiencemay be enhanced in a manner consistent with existing markets forinformational goods. This includes teasers, try-before-you buy,downgraded samples, combinations of content with advertising in the samechannel, etc.

SAMPLE EMBODIMENTS

In order to better appreciate and understand the present invention, thefollowing sample embodiments are provided. These sample embodiments areprovided for exemplary purposes only, and in no way limit the presentinvention.

Sample Embodiment 1

Although this sample embodiment may be described in relation to digitalmusic and video, it should be noted that the present invention is not solimited.

According to one embodiment of the present invention, a secured dataobject that may contain digital music or video, or both, may containindependent data embedded within. For purposes of this embodiment,digital music having an initial signal quality level equivalent to thatof a compact disc is provided.

Independent data, which may include authenticatable data, such as arobust open watermark, may be embedded into the digital music. This maybe accomplished by any known technique. The digital music is thenscrambled in order to obscure embedded data. The scrambling alsodegrades the signal quality of the digital music.

The scrambling may be used to degrade the signal quality by apredetermined amount. For example, the scrambling may decrease thesignal quality one step, or level, such as from CD quality to MP3quality; MP3 quality to FM quality; FM quality to AM quality; and AMquality to telephone quality. For video, this may include, inter alia,NTSC quality, QuickTime quality, Macrovision quality, satellite quality,and DVD quality.

The steps of embedding independent data and scrambling the digital musicmay be repeated as desired until a predetermined condition, such as adesired signal quality level, is reached.

In one embodiment, the digital music may be distributed to users with adegraded signal quality in order to promote the digital music. Forexample, users may be able to download the digital music with a degradedsignal quality (e.g., telephone quality, AM radio quality, etc.) forfree in order to evaluate the music. If the user likes the music, theuser may purchase the ability to upgrade the signal quality level of thedigital music. This may be done in steps (e.g., from telephone qualityto AM radio quality, then AM quality to FM quality, etc.) or it may bedone in one instance (e.g., telephone quality to CD quality).

Keys may be used to upgrade the signal quality. As a user purchases akey, the key is used to decode the independent data from the digitalmusic. This data may include payment information.

The keys may be used singularly, or they may be used collectively. Whenused singularly, a key may be used by an individual user to increase thesignal quality of the digital music, or a key may be used to initiate asession key-based timing mechanism. In the latter situation, the sessionkey may provide a user with a unit of time of high quality digitalmusic.

When used collectively, the keys may be used to increase the signalquality of the digital music for a group. For example, as more userspurchase keys to decode the music, the signal quality of the digitalmusic is upgraded for all. In addition, the keys may be pooled toinitiate a session key-based timing mechanism.

The pricing of the keys may be based on several pricing models. Forexample, factors, including, inter alia, signal quality, bandwidthrequired to transmit the digital music, etc., may be used in determiningthe pricing of a key.

Sample Embodiment 2

Several companies give consumers the option of receiving advertisementsin lieu of making a direct payment for the services that the companiesprovide. Examples of these services include EverAd for music, NetZeroand Juno for Internet access, etc. The present invention provides a wayto bridge a pay service with an advertisement delivery service, tocreate an individual mix for each consumer.

At a base quality level, the user may be required to view a completeadvertising package, using the maximum amount of screen space available.As the user pays for increased quality levels, the quantity and size ofthe advertisements decrease, until at full quality and/or full paymentthe advertisements disappear. The quality/advertisement ratio may beindividual for each data object as well as each consumer.

This embodiment offers several significant advantages. First, thepricing of the system may be optimized for each object individually.Second, the advertisements may be served as a stream, which maynecessitate the consumer to periodically connect to the ad server, thusmaintaining the integrity of the data objects and allowing for regularkey switching.

Sample Embodiment 3

Pay-per-view streams are one of the ways in which cable and satelliteproviders create additional revenue from their existing bandwidth. Thepresent invention provides the ability to offer a pay-per-view event ata degraded quality until a key purchase was made. Each key purchaseincrementally increases the quality of the stream. Additionally, thekeys may be switched at predetermined intervals, such as 1 second, toallow higher quality “teasers” to induce purchase. For example, aconsumer may view a one-time preview at the higher quality for 1 or 2minutes by receiving the relevant keys. This may entice the consumer topurchase the higher quality stream.

Sample Embodiment 4

The present invention may provide the ability to combine severalseparate channels into a single window. According to one embodiment, aplurality of channels or data objects with varying applications ofsecurity may be provided to a web browser. An example of such includes aweb browser with a channel of scrambled audio, watermarked advertising,and watermarked images that may be viewed and/or listened to by theuser.

The advertising may be linked to the audio channel in a manner that isdifferent from radio advertising. For example, the advertising channelmay have a logical link to the audio stream. A user may purchase ahigher quality audio signal by purchasing session keys that are linkedto the scrambling state or to the embedded watermarks. The session keysmay represent payments. Either one of the session keys, or the sessionkeys collectively, may yield authenticatable data, embedded hashes ordata related to the descrambling key(s), which may be converted in alogical manner, such as a payment estimator or “yield”-type measure, todynamically adjust the overall payment for the channel in question.

Each channel may have different data object elements, and may bedifferent for each user. The common thread for the channel may simply bethe channel name. Thus, some channels may have data objects that haveprimary value (content) and secondary value (advertising), or maycontain a specific media type (e.g., video, audio, etc.).

The yields may be personalized for a user given the fact that certainentities or aggregators of content may have many different data objectsto offer in a maximal mix that appeals to individuals or markets. In oneembodiment, certain media types may have a better yield (measured inbits/second) than other media types. An example of this is digital musicversus digital video. Digital video generally has a certain number ofbits, while digital audio has a different number of bits. The marketprices for these media types are different and the time or timesconsumers choose to listen or view means that the value in bits/secondis different. Similarly, an advertisement has a certain bandwidthprofile that is measured in terms of pricing given marketing parameters.

To the user, it is all an allocation of bandwidth given that consumershave a fixed amount of time and money to decide which media types andhow much fidelity or discreteness (media size) the user should choose ineither real time, as with a network, or in fixed prerecorded units (CDs,versus DVDs, versus recording media to handle MP3, all different mediasizes given resources available to consumers and how a media companydecides to occupy the bits).

Sample Embodiment 5

Network optimization protocols, including such technologies as cachingand store and forward models for handling the allocation of bandwidth,or more particularly data objects, are based largely on estimatingdemands for data objects by a plurality of users who may be connected tothe network in variety of ways. These users may have differing demandsbased on connection speed and other limitations for accessiblebandwidth. The ability to dynamically handle the keys described in thepresent invention, including scrambling and embedding in somepredetermined manner, also serves to enable network operators to betterdetermine what quality levels are sought on a per data object basis, andhow payments can be estimated, given user requests for keys that linkquality and payment to the objects themselves. The variety of dataobjects, based on media type and bandwidth (measured in terms of bitsper second and some predetermined quality level), is constantlymonitored to assure the best use of bandwidth for any given network. Byextension, the present invention enables any existing network to bebased more closely on dynamic pricing models and dynamic handling ofdata object dependent or channel based keys to establish real timequality levels sought but those with access to the network.

Other embodiments and uses of the invention will be apparent to thoseskilled in the art from consideration of the specification and practiceof the invention disclosed herein. The specification and examples shouldbe considered exemplary only with the true scope and spirit of theinvention indicated by the following claims. As will be easilyunderstood by those of ordinary skill in the art, variations andmodifications of each of the disclosed embodiments can be easily madewithin the scope of this invention as defined by the following claims.

1. A method comprising: receiving a digital signal in a system including at least one processor; selecting, using said at least one processor, at least one signal characteristic of the digital signal; manipulating, using said at least one processor, the at least one signal characteristic to degrade the digital signal; associating, using said at least one processor, at least one digital watermark with the degraded digital signal.
 2. The method of claim 1, wherein said manipulating comprises manipulating information independent of the digital signal.
 3. The method of claim 1, wherein said manipulating comprises manipulating format of the digital signal .
 4. The method of claim 1, wherein said manipulating comprises using at least one of a browser, viewer, player, and payment facility to degrade said digital signal.
 5. The method of claim 1, wherein said associating comprises embedding said at least one digital watermark in said degraded digital signal using at least one of a browser, viewer, player, and recorder.
 6. The method of claim 1, wherein at least one of said manipulating and said associating comprises using a key.
 7. The method of claim 1, wherein said receiving comprises downloading at least one of video data, image data, and audio data.
 8. The method of claim 1, wherein manipulating compromises inserting an advertisement.
 9. The method of claim 1, wherein said receiving said digital signal in a system comprises receiving said digital signal in a content player.
 10. A system, comprising: at least one processor; wherein said system configured to use said at least one processor to select at least one signal characteristic of a digital signal; wherein said system is configured to use said at least one processor to manipulate said at least one signal characteristic to degrade the digital signal to form a degraded digital signal; wherein said system is configured to use said at least one processor to associate with said degraded digital signal at least one digital watermark.
 11. The system of claim 10, wherein said system is configured to manipulate information independent of the digital signal.
 12. The system of claim 10, wherein said system is configured to manipulate format of said digital signal.
 13. The system of claim 10, wherein said system comprises at least one of a browser, viewer, player, and payment facility.
 14. The system of claim 10, wherein said system is configured to use a key to perform at least one of the manipulating said at least one signal characteristic and the associating said at least one digital watermark.
 15. The system of claim 10, wherein said system is configured to download said digital signal.
 16. The system of claim 15, wherein said download comprises at least one of video data, image data, and audio data.
 17. The system of claim 10, wherein said degraded digital signal comprises an advertisement.
 18. The system of claim 10, wherein said system comprises a content player. 